If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

Now that you mention it, wouldn't it be a smart thing to analyze the dependencies before the update process and uncompressing/installing packages that don't affect each other in parallel?

Even packages that do not depend on each other might need to update the same configuration file(s). Also, how do you handle failed installations? Do you abort all others, or do you wait for them to complete before failing? How do you write a log file that's actually readable (or do you write multiple log files and merge them post-install)? I'm not saying it can't be done, but it's probably too much work for too little gain.

Originally Posted by garegin

just to show the user unfriendliness of debian. it's the only major distro that does not have a single install disk. it's either netinstall, which has to pull the intall content from the internet or multiple disks. the only sane option is to use debian live which does come as a single disk

Afaik you only need the first disk for base installation, all the other disks contain optional software (at least it used to be this way the last time I used rotating media, aka. hundreds of years ago). I've gone with netinstall for the last few installations though. I need a very limited number of packages, so why would I download a full CD/DVD? Netinstall was definitely faster than download+burn.

Originally Posted by rohcQaH

By the time you've finished downloading and burning all those discs, half of the packages contained within are outdated.

You are aware you're talking about Debian, right? So unless you it takes you more than a couple years you'll probably only need to upgrade a few packages post-install

Only if the decompression algorithm isn't using all your CPUs. From what I know of LZMA, it's technically capable of being parallelized, but it's not embarrassingly parallel, so you can't just scale it up effortlessly.

I've monitored cpu usage during decompression and even with an SSD it hardly uses more than one core to decompress. Actually, even real-world compression isn't as paralleled as the synthetic benchmarks make it look like. I/O seems to be much more important, that's why I loved this idea:

Originally Posted by allquixotic

Download each package to a buffer in RAM. As they are downloading, directly wire up Xz (which is a streaming decompressor) to the buffer, so that you are decompressing in parallel with the download. (...) As it's decoding, it's writing its results to disk. So at the same time as you're pulling the data off of the network, you could even set it up so that you mmap the network buffer itself to make it a zero copy architecture, so that the data travels: NIC -> buffer in RAM -> XZ reads data from buffer (zero copy) -> XZ writes data to disk.

Then, once Xz writes the decoded data to disk, you just "mv" (re-link) the files to the correct locations.

Installation of packages would go from taking many minutes to taking exactly as long as it takes to download the packages. And the effect would be better the slower your internet connection is.

As for the dependencies it would require that the package contents can be read without the package being completely downloaded and the package metadata is the first thing in the file. Or something like that. Maybe a kind of uncompressed package that contains an information file and the actual compressed package contents. Does this exist? I mean, in the open-source world.

Anyway, even decompressing while downloading would probably also provide some gains by itself.

As for the dependencies it would require that the package contents can be read without the package being completely downloaded and the package metadata is the first thing in the file. Or something like that. Maybe a kind of uncompressed package that contains an information file and the actual compressed package contents. Does this exist? I mean, in the open-source world.

Anyway, even decompressing while downloading would probably also provide some gains by itself.

The metadata (including dependency info) is already available in a separate file for all modern distros. For Fedora it's usually in a file called something like primary.xml.gz (or xz). The file is several megabytes worth of dependency info. If you didn't have this up-front, then figuring out how to "yum install" some package would involve downloading EVERY package in the repository to figure out the dependency graph.

To put it simply, you are under-estimating the information we already have available. You can assume that cheaply/efficiently obtaining the dependency graph for the desired packages is an easy and standard feature for Linux package managers.

BTW, the compression / decompression memory for LZMA/LZMA2 (of which Xz is just one implementation) is asymmetrical. I... about 64 MB total (and that memory will get allocated, then freed, then re-allocated again as each dpkg process unpacks a different archive file).

I'm aware of all of that. 64mb to decompress one archive is _way_ too much.

As for dpkg not supporting parallel installation, I haven't used Debian in about five years. I'd have thought them to have improved in this time, as even back then it was rather annoying to be unable to install something else in another terminal when one apt-get was doing its thing.

(yes, that problem could be solved simply by queuing. But true parallel install should be possible.)

Software on a stick.

I like the idea of having one big image to put on a usb stick. Could this be an iso bigger than the 4gig limit - is there a way to make an 80gig iso image to put on a usb 3.0 stick? All top quality free software tons on one stick.

Rediculous

Debian packages are an ar archive (same as static libraries), containing 2 compressed tarballs: the first has metadata, the second has the package content. I think they want to move from tar.gz to tar.xz for these two tarballs.
Debian policy requires that anything that can be compressed must be. That includes manpages, fonts, and much of the documentation. Besides that, you have shell scripts and stripped binaries (plus debug symbols for some). There isn't much that's highly compressible.
It's quite possible to install from 1 CD; however, the "Debian operating system" includes every package in main. Hence a 73-CD media set; almost noone wants all of it, but it is available (for those who want to set up a workstation offline, or such).
Last time I tried installing everything (press + over uninstalled in aptitude), there were ~400 conflicts, it would take ~90 GB, and it took nearly 2 minutes to resolve the order. The archives are a lot larger now, so it might be near 200 GB.
The install media they're talking about is for the next Debian stable; that means you might have a DVD or two worth of updates by the next release. And yes, they do offer a disk containing all updates.
A minimal install of Debian is around 300 MB. It will run on i486, with minimum RAM in the 32-64 MB range.

Does anyone know of a distro that does real package management and allows parallel operations?
Systems that don't handle dependencies are irrelevant; I mean something where you can't get a race condition by say starting gnome install and then (while that's in progress) uninstalling GTK.

I like the idea of having one big image to put on a usb stick. Could this be an iso bigger than the 4gig limit - is there a way to make an 80gig iso image to put on a usb 3.0 stick? All top quality free software tons on one stick.